Wireless communication systems have become a prevalent means by which a majority of people worldwide have come to communicate. Wireless communication devices have become smaller and more powerful in order to meet consumer needs and to improve portability and convenience. The increase in processing power in mobile devices such as cellular telephones has lead to an increase in demands on wireless network transmission systems. Such systems typically are not as easily updated as the cellular devices that communicate there over. As mobile device capabilities expand, it can be difficult to maintain an older wireless network system in a manner that facilitates fully exploiting new and improved wireless device capabilities.
Wireless communication systems generally utilize different approaches to generate transmission resources in the form of channels. These systems may be code division multiplexing (CDM) systems, frequency division multiplexing (FDM) systems, and time division multiplexing (TDM) systems. One commonly utilized variant of FDM is orthogonal frequency division multiplexing (OFDM) that effectively partitions the overall system bandwidth into multiple orthogonal subcarriers. These subcarriers may also be referred to as tones, bins, and frequency channels. Each subcarrier can be modulated with data. With time division based techniques, each subcarrier can be used in all or a portion of sequential time slices or time slots. Each user may be provided with one or more time slot and subcarrier combinations for transmitting and receiving information in a defined burst period or frame. The hopping schemes may generally be a symbol rate hopping scheme or a block hopping scheme.
Code division based techniques typically transmit data over a number of frequencies available at any time in a range. In general, data is digitized and spread over available bandwidth, wherein multiple users can be overlaid on the channel and respective users can be assigned a unique sequence code. Users can transmit in the same wide-band chunk of spectrum, wherein each user's signal is spread over the entire bandwidth by its respective unique spreading code. This technique can provide for sharing, wherein one or more users can concurrently transmit and receive. Such sharing can be achieved through spread spectrum digital modulation, wherein a user's stream of bits is encoded and spread across a very wide channel in a pseudo-random fashion. The receiver is designed to recognize the associated unique sequence code and undo the randomization in order to collect the bits for a particular user in a coherent manner.
A typical wireless communication network (e.g., employing frequency, time, and/or code division techniques) includes one or more base stations that provide a coverage area and one or more mobile (e.g., wireless) terminals that can transmit and receive data within the coverage area. A typical base station can simultaneously transmit multiple data streams for broadcast, multicast, and/or unicast services, wherein a data stream is a stream of data that can be of independent reception interest to a mobile terminal. A mobile terminal within the coverage area of that base station can be interested in receiving one, more than one or all the data streams transmitted from the base station. Likewise, a mobile terminal can transmit data to the base station or another mobile terminal. In these systems the bandwidth and other system resources are assigned utilizing a scheduler.
As wireless systems have developed over time, service provides have acquired the right to use one or more frequency bands but not others to which they have not purchased the communications rights. This has resulted in cases where a service provider may own the right to use multiple discontinuous portions of bandwidth in a geographic region but be precluded from using bandwidth located between the discontinuous portions of bandwidth to which the service provider has acquired rights.
Discontinuous portions of bandwidth might be used individually, e.g., by one wireless terminal or base station communicating using one discontinuous portion of bandwidth at a time. However, from a frequency diversity and/or throughput perspective it may be desirable for a wireless terminal or base station to be able to use multiple discontinuous portions of bandwidth at the same time, e.g., to support communication in one or multiple directions. For example, in the case of a need to support high uplink or downlink data rates it might be desirable to be able to use multiple discontinuous portions of bandwidth, e.g., portions of bandwidth separated by another service providers carrier, to support communication in an uplink direction or a downlink direction depending on which direction had the need for a high data throughput.
In view of the above, it should be apparent that there is a need for methods and apparatus which would allow a base station and/or wireless terminals to use discontinuous portions of bandwidth without using portions of bandwidth in between the discontinuous bands. It would be desirable if at least some methods and apparatus were well suited for use where the discontinuous bands were separated by a bandwidth corresponding to the width of a service provider's carrier, e.g., 1.25 MHz or more in some cases.